When a client wants to call a server, the executing application usually has to perform certain checks to see whether the client has sufficient access rights and whether the specific server has the appropriate capabilities or is even suitable for certain functionality.
Usually, this is a tedious validation task for an application. But, not only must the security restrictions be checked, but also the capabilities, preferences, environment, etc. influence the decision as to whether the client has access and capabilities. Moreover, a specific characterization is easily forgotten.
A conventional authorization check and Access Control List (ACL) provides for a mathematical intersection of the clients rights against the servers capabilities. However, an ACL is not flexible.
In WO 2008015398, the author describes a method of web service selection without (much) user intervention. This is mainly a selection by relevance, but no configuration or mediation. EP 2012490 A1 discloses a middleware to find a server/servers out of a pool which provide the functionality needed by a client request. Scientific articles or patents may describe a method of web service which is mainly a selection by relevance without configuration or mediation; or middleware that finds one or more servers from a pool, to provide the functionality needed by client request. None of these addresses the problems noted above.